<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		
	</head>
	<body>
		<iframe id="iframe" src="http://localhost:81/bg5/" style="width: 100%;height: 600px;" onloadstart="">
			
		</iframe>
		<script type="text/javascript">
		alert(Object.defineProperty())
			var iframe=document.getElementById("iframe");
			iframe.oncommand =function(event){
				
				alert(iframe.readyState);
				
			}
		</script>
	</body>
</html>
